|Publication number||US6686212 B1|
|Application number||US 10/286,100|
|Publication date||3 Feb 2004|
|Filing date||31 Oct 2002|
|Priority date||31 Oct 2002|
|Publication number||10286100, 286100, US 6686212 B1, US 6686212B1, US-B1-6686212, US6686212 B1, US6686212B1|
|Inventors||John F. Conley, Jr., Yoshi Ono, Rajendra Solanki|
|Original Assignee||Sharp Laboratories Of America, Inc.|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (8), Non-Patent Citations (2), Referenced by (81), Classifications (40), Legal Events (4)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This application is related to Ser. No. 09/894,941, filed Jun. 28, 2001, for Method to Initiate the Atomic Layer Deposition of a High Dielelctric Constant Material Directly on a Silicon Substrate.
This invention relates to integrated circuit fabrication, and specifically to a method of fabricating a MOS gate dielectric for separating a transistor gate from the channel between the source and drain regions.
Thermally grown SiO2 on silicon has been called the “heart and soul” of MOS technology. The Si/SiO2 interface has excellent semiconductor properties including low interface and bulk trapping, thermal stability, high breakdown, etc. With each successive generation of microelectronic technology, however, the thickness of the gate dielectric is scaled. e.g., becomes smaller. As the thickness is scaled below 1.5 nm, problems arise, such as excessive power consumption due to leakage from direct tunneling, boron penetration, reliability concerns, etc. Because of these problems, in the near future, possibly as early as the 80 nm node in 2005, the reign of SiO2 as a gate dielectric may dwindle, eventually coming to an end. SiO2 will likely be replaced by a higher dielectric constant (κ) material, which will have a greater thickness for any given capacitance.
Despite this compelling near term need for an SiO2 substitute, a suitable replacement still has not been discovered. Requirements for this replacement material include lower leakage, low interface traps, low trapped charge, good reliability, good thermal stability, conformal deposition, etc. Promising candidate materials include metal oxides such as HfO2, ZrO2, etc., and other metal oxides.
It is crucial to avoid a low-κ interfacial layer when depositing a high-κ film, as even a very thin low-κ layer can negate most of the benefits of the overlying high-κ material. It is therefore essential to deposit a high-κ material directly on H-terminated silicon layer.
Because of the requirements for conformality and thickness control, atomic layer deposition (ALD) has emerged as one of the most promising deposition techniques for high-κ material. In this technique, dielectric material is built up layer-by-layer in a self-limiting fashion, i.e., the deposition phenominnon where only one monolayer of a chemical species will adsorb onto a given surface. Currently, the leading ALD precursors for depositing metal oxides are metal halides and metal organics. There has also been some experimentation using anhydrous metal nitrates as high-κ dielectric precursors.
A film of ZrO2, deposited using a metal chloride precursor, such as ZrCl4 have shown good insulating properties, including a high-κ dielectric constant and low leakage. A major drawback of ZrCl4, however, is that it does not provide for smooth deposition directly on H-terminated silicon, requires several “incubation” cycles, and requires a thin layer of SiO2 for uniform initiation. These problems must be solved before metal-chloride precursors can be used in production.
A drawback of the metal organic precursors is the potential for organic contamination. Hf(NO3)4 has been demonstrated as a viable ALD precursor, as identified in the above-identified related Application, and in Conley, Jr., et al., Atomic Layer Deposition of Hafnium Oxide Using Anhydrous Hafnium Nitrate, Electrochem. and Sol. State Lett. 5 (5) May, 2002. The primary benefit of Hf(NO3)4 is that it allows deposition initiation directly on H-terminated silicon, resulting in a uniform thin layer. This method has the potential to avoid a low-κ interfacial layer, however, experimental work has shown that HfO2 films deposited via ALD of Hf(NO3)4 have a dielectric constant which is lower than expected, possibly because of the oxygen-rich nature of the films. The “bulk” dielectric properties of the resulting films must be improved before metal-nitrate precursors can find widespread use.
A method of forming a layer of high-κ dielectric material in an integrated circuit includes preparing a silicon substrate; depositing a first layer of metal oxide using ALD with a metal nitrate precursor; depositing another layer of metal oxide using ALD with a metal chloride precursor; and completing the integrated circuit.
It is an object of the invention to deposit a metal oxide high-κ layer on a silicon substrate.
Another object of the invention is to deposit a metal oxide high-κ layer on a silicon substrate without the requirement of forming a low-κ interfacial layer on the silicon substrate.
A further object of the invention is to provide a high-κ layer having low leakage properties.
This summary and objectives of the invention are provided to enable quick comprehension of the nature of the invention. A more thorough understanding of the invention may be obtained by reference to the following detailed description of the preferred embodiment of the invention in connection with the drawings.
FIG. 1 depicts a silicon substrate having a H-terminated silicon surface.
FIG. 2 depicts the substrate after deposition of an initial HfO2 layer.
FIG. 3 depicts the structure after deposition of the second, or final, HfO2 layer.
The state-of-the-art technique for gate formation requires oxidation of silicon at high temperatures. It is likely that SiO2 will be replaced by a metal-oxide, such as HfO2, ZrO2, etc. Although a high-κ deposition method has not been established yet, a leading technique is atomic layer deposition (ALD). ALD is typically performed using a single precursor, such as a metal tetrachloride, metal organic, or anhydrous metal nitrate. As described above, these precursors all have significant disadvantages.
Because the leading precursors currently available for ALD of metal oxides have serious drawbacks, the method of the invention incorporates a combination of precursors to improve the quality of the resulting metal-oxide films. The combination of precursors draws on the advantages of each precursor, while minimizing the disadvantages associated with using the precursors. The method of the invention initiates ALD deposition on H-terminated silicon with a single, or up to five, Hf(NO3)4 cycles, followed by ALD deposition of the remaining film to desired thickness using another precursor such as HfCl4. The method of the invention eliminates the need for an initial low-κ interfacial layer, while still achieving a “bulk” film with a high dielectric constant.
The method of the invention incorporates the strengths of individual precursors, in combination, to achieve deposition of a high-κ film directly on H-terminated silicon. A Hf(NO3)4 precursor provides initiation directly on H-terminated silicon and provides a base layer for further ALD using a precursor of HfCl4.
The use of alternate precursors has been previously described, however, use of such alternate precursors has meant using different precursors to interleave different metal oxides, such as HfO2—ZrO2, Ta2O5—HfO2, etc., to create a nano-laminate, as described in H. Zhang, et al., High Permittivity Thin Film Nanolaminates, J. Appl. Phys. 87, 1921 (2000). The combination of different precursors to deposit the same metal oxide using multiple deposition cycles is not known to have been reported.
The method of the invention describes a method of gate oxide deposition using ALD. The first, or up to five, ALD deposition cycle(s) use anhydrous hafnium nitrate (Hf(NO3)4) as the precursor, while the remaining cycles use hafnium tetra-chloride (HfCl4) as the precursor. One ALD deposition cycle includes a pulse of the precursor, either hafnium nitrate or hafnium tetra-chloride, followed by a nitrogen purge, and then a pulse of water vapor, and finally, another nitrogen purge.
Referring now to FIG. 1, the structure prior to depositing the gate oxide is formed by any state-of-the-art method, which includes preparing a silicon substrate 10 and field oxide regions 12, 14. The example shown in the figures below is for a replacement gate process. The last step prior to forming the gate oxide is to expose the silicon surface to HF to prepare a H-terminated silicon surface 16.
FIG. 2 depicts the initial, or first layer, 18 of HfO2, which is deposited via ALD using a Hf(NO3)4 precursor. The purpose of this step is to initiate deposition directly on H-terminated silicon without the need for an “incubation” period or a thin SiO2 layer. The initial layer may be form between about 0.1 nm to 1.5 nm thick.
FIG. 3 depicts the another HfO2 “bulk” layer 20 as deposited to a desired thickness, which, in the preferred embodiment, is between about 3 nm to 10 nm thick, using a HfCl4 precursor. This purpose of this step is to create a “bulk” HfO2 film with the expected high dielectric constant.
The fabrication process of the method of the invention then proceeds with the deposition of the gate material, such as a metal gate followed by either and etching process or by CMP. The remaining steps are conventional fabrication processes, well known to those of ordinary skill in the art. The method of the invention eliminates the need for an initial low-κ interfacial layer while still achieving a film with a high dielectric constant.
HfO2 film A was deposited via a single cycle of ALD using a Hf(NO3)4 precursor, followed by 40 cycles of ALD using a HfCl4 precursor. As a comparison, a HfO2 film B was deposited without the single cycle ALD nitrate step, using only 40 cycles of HfCl4 precursor-based ALD. Spectroscopic ellipsometry measurements revealed that HfO2 film A, deposited using the initial ALD nitrate cycle, had an average thickness of 8.0 nm and a standard deviation of 0.5 nm. Film B, deposited without the nitrate cycle, had a average thickness of 4.2 nm and a standard deviation of 1.8 nm. The fact that film A is smoother and thicker than film B demonstrates the utility of the method of the invention: initial deposition by a single ALD cycle of Hf(NO3)4 produces an effective initiation layer for subsequent ALD using HfCl4. The fact that film A is thicker indicates that the “incubation” cycles typical of HfCl4 ALD are not required.
The layer deposited with one, or up to five, ALD cycle(s) using a Hf(NO3)4 precursor may be used as an initiation layer for ALD using other precursors, such as other metal halides, such as MI4, MBr4, etc., or metallorganics, such as alkoxide, acetylacetonates, t-butoxide, ethoxide, etc. In addition to the HfO2 process described herein, other metal oxides, such as ZrO2, Gd2O3, La2O3, CeO2, TiO2, Y2O3, Ta2O5, Al2O3, etc. may also be deposited.
Thus, a method to deposit a stacked high-κ gate dielectric for CMOS applications has been disclosed. It will be appreciated that further variations and modifications thereof may be made within the scope of the invention as defined in the appended claims.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US6013553 *||15 Jul 1998||11 Jan 2000||Texas Instruments Incorporated||Zirconium and/or hafnium oxynitride gate dielectric|
|US6203613 *||19 Oct 1999||20 Mar 2001||International Business Machines Corporation||Atomic layer deposition with nitrate containing precursors|
|US6297539 *||6 Jul 2000||2 Oct 2001||Sharp Laboratories Of America, Inc.||Doped zirconia, or zirconia-like, dielectric film transistor structure and deposition method for same|
|US20020130340 *||30 Apr 2002||19 Sep 2002||Yanjun Ma||Method of forming a multilayer dielectric stack|
|US20020153579 *||19 Apr 2002||24 Oct 2002||Nec Corporation||Semiconductor device with thin film having high permittivity and uniform thickness|
|US20020173130 *||11 Feb 2002||21 Nov 2002||Pomerede Christophe F.||Integration of High K Gate Dielectric|
|US20020197789 *||25 Jun 2001||26 Dec 2002||International Business Machines Corporation||High mobility fets using al2o3 as a gate oxide|
|US20030049942 *||22 Aug 2002||13 Mar 2003||Suvi Haukka||Low temperature gate stack|
|1||H. Zhang et al., High permittivity thin film nanolaminates, J. Appl. Phys. 87, 1921 (2000).|
|2||John F. Conley, Jr., et al., Atomic Layer Deposition of Hafnium Oxide Using Anhydrous Hafnium Nitrate, Electrochem. and Sol. State Lett. 5 (5) May, 2002.|
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|US7135369||31 Mar 2003||14 Nov 2006||Micron Technology, Inc.||Atomic layer deposited ZrAlxOy dielectric layers including Zr4AlO9|
|US7183186||22 Apr 2003||27 Feb 2007||Micro Technology, Inc.||Atomic layer deposited ZrTiO4 films|
|US7192824||24 Jun 2003||20 Mar 2007||Micron Technology, Inc.||Lanthanide oxide / hafnium oxide dielectric layers|
|US7192892 *||4 Mar 2003||20 Mar 2007||Micron Technology, Inc.||Atomic layer deposited dielectric layers|
|US7312494||31 Aug 2004||25 Dec 2007||Micron Technology, Inc.||Lanthanide oxide / hafnium oxide dielectric layers|
|US7390756||28 Apr 2005||24 Jun 2008||Micron Technology, Inc.||Atomic layer deposited zirconium silicon oxide films|
|US7442415 *||11 Apr 2003||28 Oct 2008||Sharp Laboratories Of America, Inc.||Modulated temperature method of atomic layer deposition (ALD) of high dielectric constant films|
|US7494939||31 Aug 2004||24 Feb 2009||Micron Technology, Inc.||Methods for forming a lanthanum-metal oxide dielectric layer|
|US7498247||23 Feb 2005||3 Mar 2009||Micron Technology, Inc.||Atomic layer deposition of Hf3N4/HfO2 films as gate dielectrics|
|US7508648||8 Feb 2005||24 Mar 2009||Micron Technology, Inc.||Atomic layer deposition of Dy doped HfO2 films as gate dielectrics|
|US7662729||28 Apr 2005||16 Feb 2010||Micron Technology, Inc.||Atomic layer deposition of a ruthenium layer to a lanthanide oxide dielectric layer|
|US7670646||5 Jan 2007||2 Mar 2010||Micron Technology, Inc.||Methods for atomic-layer deposition|
|US7687409||29 Mar 2005||30 Mar 2010||Micron Technology, Inc.||Atomic layer deposited titanium silicon oxide films|
|US7719065||29 Aug 2005||18 May 2010||Micron Technology, Inc.||Ruthenium layer for a dielectric layer containing a lanthanide oxide|
|US7728626||5 Sep 2008||1 Jun 2010||Micron Technology, Inc.||Memory utilizing oxide nanolaminates|
|US7863667||26 Aug 2005||4 Jan 2011||Micron Technology, Inc.||Zirconium titanium oxide films|
|US7867919||8 Dec 2006||11 Jan 2011||Micron Technology, Inc.||Method of fabricating an apparatus having a lanthanum-metal oxide dielectric layer|
|US7915174||22 Jul 2008||29 Mar 2011||Micron Technology, Inc.||Dielectric stack containing lanthanum and hafnium|
|US7960803||26 Jan 2009||14 Jun 2011||Micron Technology, Inc.||Electronic device having a hafnium nitride and hafnium oxide film|
|US7989285||23 Feb 2009||2 Aug 2011||Micron Technology, Inc.||Method of forming a film containing dysprosium oxide and hafnium oxide using atomic layer deposition|
|US8026161||30 Aug 2001||27 Sep 2011||Micron Technology, Inc.||Highly reliable amorphous high-K gate oxide ZrO2|
|US8076249||24 Mar 2010||13 Dec 2011||Micron Technology, Inc.||Structures containing titanium silicon oxide|
|US8084808||20 May 2008||27 Dec 2011||Micron Technology, Inc.||Zirconium silicon oxide films|
|US8110469||7 Feb 2012||Micron Technology, Inc.||Graded dielectric layers|
|US8154066||1 Dec 2006||10 Apr 2012||Micron Technology, Inc.||Titanium aluminum oxide films|
|US8228725||28 May 2010||24 Jul 2012||Micron Technology, Inc.||Memory utilizing oxide nanolaminates|
|US8237216||29 Oct 2010||7 Aug 2012||Micron Technology, Inc.||Apparatus having a lanthanum-metal oxide semiconductor device|
|US8278225||12 Oct 2009||2 Oct 2012||Micron Technology, Inc.||Hafnium tantalum oxide dielectrics|
|US8399365||12 Dec 2011||19 Mar 2013||Micron Technology, Inc.||Methods of forming titanium silicon oxide|
|US8445952||30 Oct 2009||21 May 2013||Micron Technology, Inc.||Zr-Sn-Ti-O films|
|US8481395||1 Aug 2011||9 Jul 2013||Micron Technology, Inc.||Methods of forming a dielectric containing dysprosium doped hafnium oxide|
|US8501563||13 Sep 2012||6 Aug 2013||Micron Technology, Inc.||Devices with nanocrystals and methods of formation|
|US8524618||13 Sep 2012||3 Sep 2013||Micron Technology, Inc.||Hafnium tantalum oxide dielectrics|
|US8541276||9 Apr 2012||24 Sep 2013||Micron Technology, Inc.||Methods of forming an insulating metal oxide|
|US8558325||17 May 2010||15 Oct 2013||Micron Technology, Inc.||Ruthenium for a dielectric containing a lanthanide|
|US8652957||26 Sep 2011||18 Feb 2014||Micron Technology, Inc.||High-K gate dielectric oxide|
|US8742515||3 Jul 2013||3 Jun 2014||Micron Technology, Inc.||Memory device having a dielectric containing dysprosium doped hafnium oxide|
|US8907486||11 Oct 2013||9 Dec 2014||Micron Technology, Inc.||Ruthenium for a dielectric containing a lanthanide|
|US8921914||5 Aug 2013||30 Dec 2014||Micron Technology, Inc.||Devices with nanocrystals and methods of formation|
|US8951903||3 Feb 2012||10 Feb 2015||Micron Technology, Inc.||Graded dielectric structures|
|US20030045078 *||30 Aug 2001||6 Mar 2003||Micron Technology, Inc.||Highly reliable amorphous high-K gate oxide ZrO2|
|US20030207032 *||2 May 2002||6 Nov 2003||Micron Technology, Inc.||Methods, systems, and apparatus for atomic-layer deposition of aluminum oxides in integrated circuits|
|US20040137678 *||30 Jun 2003||15 Jul 2004||Cho Ho Jin||Method for forming capacitor of semiconductor device|
|US20040175882 *||4 Mar 2003||9 Sep 2004||Micron Technology, Inc.||Atomic layer deposited dielectric layers|
|US20040203254 *||11 Apr 2003||14 Oct 2004||Sharp Laboratories Of America, Inc.||Modulated temperature method of atomic layer deposition (ALD) of high dielectric constant films|
|US20040214399 *||22 Apr 2003||28 Oct 2004||Micron Technology, Inc.||Atomic layer deposited ZrTiO4 films|
|US20050020017 *||24 Jun 2003||27 Jan 2005||Micron Technology, Inc.||Lanthanide oxide / hafnium oxide dielectric layers|
|US20050029547 *||31 Aug 2004||10 Feb 2005||Micron Technology, Inc.||Lanthanide oxide / hafnium oxide dielectric layers|
|US20050029604 *||31 Aug 2004||10 Feb 2005||Micron Technology, Inc.||Atomic layer deposited Zr-Sn-Ti-O films using TiI4|
|US20050029605 *||31 Aug 2004||10 Feb 2005||Micron Technology, Inc.||Highly reliable amorphous high-k gate oxide ZrO2|
|US20050034662 *||31 Aug 2004||17 Feb 2005||Micro Technology, Inc.||Methods, systems, and apparatus for uniform chemical-vapor depositions|
|US20050054165 *||31 Mar 2003||10 Mar 2005||Micron Technology, Inc.||Atomic layer deposited ZrAlxOy dielectric layers|
|US20050087134 *||31 Aug 2004||28 Apr 2005||Micron Technology, Inc.||Methods, systems, and apparatus for uniform chemical-vapor depositions|
|US20050110069 *||7 Apr 2004||26 May 2005||Hynix Semiconductor Inc.||Hafnium oxide and aluminium oxide alloyed dielectric layer and method for fabricating the same|
|US20050280067 *||26 Aug 2005||22 Dec 2005||Micron Technology, Inc.||Atomic layer deposited zirconium titanium oxide films|
|US20060001151 *||26 Aug 2005||5 Jan 2006||Micron Technology, Inc.||Atomic layer deposited dielectric layers|
|US20060003517 *||29 Aug 2005||5 Jan 2006||Micron Technology, Inc.||Atomic layer deposited Zr-Sn-Ti-O films using TiI4|
|US20060043492 *||29 Aug 2005||2 Mar 2006||Micron Technology, Inc.||Ruthenium gate for a lanthanide oxide dielectric layer|
|US20060043504 *||31 Aug 2004||2 Mar 2006||Micron Technology, Inc.||Atomic layer deposited titanium aluminum oxide films|
|US20060046505 *||26 Aug 2004||2 Mar 2006||Micron Technology, Inc.||Ruthenium gate for a lanthanide oxide dielectric layer|
|US20060046522 *||31 Aug 2004||2 Mar 2006||Micron Technology, Inc.||Atomic layer deposited lanthanum aluminum oxide dielectric layer|
|US20060125030 *||13 Dec 2004||15 Jun 2006||Micron Technology, Inc.||Hybrid ALD-CVD of PrxOy/ZrO2 films as gate dielectrics|
|US20060128168 *||13 Dec 2004||15 Jun 2006||Micron Technology, Inc.||Atomic layer deposited lanthanum hafnium oxide dielectrics|
|US20060176645 *||8 Feb 2005||10 Aug 2006||Micron Technology, Inc.||Atomic layer deposition of Dy doped HfO2 films as gate dielectrics|
|US20060189154 *||23 Feb 2005||24 Aug 2006||Micron Technology, Inc.||Atomic layer deposition of Hf3N4/HfO2 films as gate dielectrics|
|US20060223337 *||29 Mar 2005||5 Oct 2006||Micron Technology, Inc.||Atomic layer deposited titanium silicon oxide films|
|US20060244100 *||28 Apr 2005||2 Nov 2006||Micron Technology, Inc.||Atomic layer deposited zirconium silicon oxide films|
|US20060255470 *||25 Jul 2006||16 Nov 2006||Micron Technology, Inc.||ZrAlxOy DIELECTRIC LAYERS|
|US20060261397 *||26 Jul 2006||23 Nov 2006||Micron Technology, Inc.||Lanthanide oxide/hafnium oxide dielectric layers|
|US20070037415 *||20 Oct 2006||15 Feb 2007||Micron Technology, Inc.||Lanthanum hafnium oxide dielectrics|
|US20070048953 *||30 Aug 2005||1 Mar 2007||Micron Technology, Inc.||Graded dielectric layers|
|US20070059881 *||13 Nov 2006||15 Mar 2007||Micron Technology, Inc.||Atomic layer deposited zirconium aluminum oxide|
|US20070181931 *||13 Apr 2007||9 Aug 2007||Micron Technology, Inc.||Hafnium tantalum oxide dielectrics|
|US20080217676 *||20 May 2008||11 Sep 2008||Micron Technology, Inc.||Zirconium silicon oxide films|
|US20080220618 *||20 May 2008||11 Sep 2008||Micron Technology, Inc.||Zirconium silicon oxide films|
|US20090032910 *||22 Jul 2008||5 Feb 2009||Micron Technology, Inc.||Dielectric stack containing lanthanum and hafnium|
|US20090155976 *||23 Feb 2009||18 Jun 2009||Micron Technology, Inc.||Atomic layer deposition of dy-doped hfo2 films as gate dielectrics|
|US20100029054 *||4 Feb 2010||Ahn Kie Y||Hafnium tantalum oxide dielectrics|
|US20100044771 *||30 Oct 2009||25 Feb 2010||Ahn Kie Y||Zr-Sn-Ti-O FILMS|
|US20110037117 *||17 Feb 2011||Ahn Kie Y||Lanthanum-metal oxide dielectric apparatus, methods, and systems|
|US20130207171 *||3 Jan 2013||15 Aug 2013||Elpida Memory, Inc.||Semiconductor device having capacitor including high-k dielectric|
|U.S. Classification||438/3, 257/310, 257/E21.29, 257/E21.639, 257/E21.444, 257/295, 257/E21.274, 257/E21.01, 438/240|
|International Classification||H01L21/02, H01L29/78, C23C16/40, H01L21/28, H01L29/51, H01L21/8238, H01L21/336, C23C16/455, C23C16/44, H01L21/283, H01L21/316, H01L21/31|
|Cooperative Classification||H01L21/823857, H01L21/3141, C23C16/45529, H01L29/513, C23C16/405, H01L21/31683, H01L21/31604, H01L28/56, H01L29/66545, H01L21/28194, H01L29/518, H01L29/517|
|European Classification||H01L29/66M6T6F8, H01L21/28E2C2D, C23C16/40H, H01L29/51B2, H01L21/8238J, H01L21/314A, C23C16/455F2B2|
|31 Oct 2002||AS||Assignment|
Owner name: SHARP LABORATORIES OF AMERICA, INC., WASHINGTON
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:CONLEY, JOHN F. JR.;ONO, YOSHI;SOLANKI, RAJENDRA;REEL/FRAME:013483/0556;SIGNING DATES FROM 20021030 TO 20021031
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